This section provides background information related to the present disclosure which is not necessarily prior art.
In a gas-fired storage water heater, a flame for heating the water is produced in the presence of three elements: a flammable substance (gas), air, and heat. The air is from the atmosphere and the heat may initially be provided, e.g., by an igniter system of the heater. A gas burner acts to heat the water in a tank. Gas-fired water heaters can typically be used with three different types of supply gas: natural gas (having a low specific gravity), propane and natural gas/butane mix (having a high specific gravity). Higher specific gravity gases tend to move at lower velocities than lower specific gravity gases.